US Patent 7179164 Chimney cap apparatus and method

A cap for a flue opening of a chimney in order to enhance draw of smoke and in order to protect from entry of animals, debris, and the elements. The device includes a tubular housing having sidewalls fabricated from flat sheet metal and a top attached to the sidewalls from fasteners. A plurality of louver openings are provided in the sidewalls in order to draw air. A plurality of exit vent openings in the sidewalls above the louver openings are at least equal to a cross-sectional area of the flue opening. An inner frame and mounting assembly includes a mechanism to both anchor the device to the chimney flue and to level the device.